1000 VA · 120VAC · Lithium Rack UPS · Platform Comparison

P91-1kLi vs APC Smart-UPS SMTL1000RM2UCNC

The P91-1kLi and APC Smart-UPS SMTL1000RM2UCNC are both 1000 VA lithium UPS systems with different architectures. The P91-1kLi is online double-conversion; the SMTL1000 is line-interactive. The P91-1kLi adds LiFePO₄ chemistry, operation up to 50 °C, optional wall-mount capability with PV-WMB, TAA compliance, and a 6-year warranty.

Xtreme Power
P91-1kLi
vs
APC
Smart-UPS SMTL1000RM2UCNC
Where the P91 Li leads

What the P91 Li brings

  • Online double-conversion vs line-interactive topology
  • LiFePO₄ chemistry for lifecycle and thermal stability
  • Operation up to 50 °C for edge and non-conditioned sites
  • Rack, tower, or wall deployment
  • TAA compliance and a 6-year warranty
Side-by-side

Side-by-side specifications

SpecificationXtreme Power P91-1kLiAPC Smart-UPS SMTL1000RM2UCNCAdvantage
TopologyOnline double-conversionLine-interactiveP91 Li – full double-conversion
Battery chemistryLiFePO₄Lithium-ionP91 Li – LiFePO₄
Battery design lifeUp to 15 years8–10 years typicalP91 Li – longer lifecycle
Capacity range1000 VA (1kLi)1000 VA (SMTL1000RM2UCNC)Matched capacity
RuntimeInternalInternalComparable
Individual outlet controlNoNoNot in this class
Temperature ratingUp to 50°C40°C typicalP91 Li – higher-temp operation
DeploymentRack / tower / wall (with PV-WMB)Rack / towerP91-1kLi – wall-mount option available
TAA complianceYes (standard)Yes (US suffix models only)P91 Li – TAA standard, no suffix needed
Warranty6 years (UPS + battery)5 yearsP91 Li – longer warranty

Specifications from Xtreme Power’s supplied P91 Li vs APC Smart-UPS SMTL comparison; confirm against current vendor documentation. The SMTL1000RM2UCNC is line-interactive; the P91 Li is online double-conversion. TAA compliance note: P91 Li models are TAA-compliant as standard. APC Smart-UPS SMTL models require the “US” suffix designation (e.g., SMTL1000RM2UCUS) to meet Trade Agreements Act requirements for federal procurement; the SMTL1000RM2UCNC model shown here does not include US TAA compliance.

Where each fits

Choosing between them

At 1000 VA, both systems target the same capacity. The core difference is topology: the P91 Li fully isolates loads via double-conversion, while the line-interactive SMTL regulates voltage without full isolation. The P91 Li adds higher-temperature operation (up to 50°C), optional wall-mount (with PV-WMB), TAA compliance, and a longer warranty. The APC offers integrated network management out of the box.

Choose the P91 Li if you need

  • True online double-conversion protection
  • LiFePO₄ and operation up to 50°C
  • Edge or non-conditioned environments
  • TAA compliance and extended warranty

The Smart-UPS SMTL may fit if you need

  • A line-interactive UPS for cost-sensitive deployments
  • Voltage regulation without full double-conversion
  • Integrated network management built-in
  • Alignment with the APC Smart-UPS ecosystem

Comparing 1000 VA lithium UPS options?

The P91-1kLi brings online double-conversion, LiFePO₄, up to 50°C operation, and TAA compliance to the 1000 VA segment—with higher protection than line-interactive alternatives and longer battery lifecycle.